OT: Ceres more interesting than previously thought
 

Found this interesting link at Adastra. I've always felt a little sorry for Ceres. Just because it's in the same orbit as the asteroid belt ppl call it an asteroid. I think it should be a planet, and now astronomers are coming round to my way of thinking:

http://hubblesite.org/newscenter/new.../2005/27/text/

OK, lets strap some boosters to that baby, drag it into a more sensible orbit, let all that ice melt, install a bit of atmosphere and then build ourselves a planet-wide low-grav water park and whale sanctuary!

Re: OT: Ceres more interesting than previously tho
 

Let's not forget the most important reason - Slushie Mining Port.

Re: OT: Ceres more interesting than previously tho
 

Interesting...thanks for the link.

At 580 miles diameter, Ceres makes a mighty small planet, and size-wise it's more like many planetary moons. But I suppose, being that it's in orbit around the sun rather than one of the planets, it might qualify. The question then becomes: How big is big enough?

Re: OT: Ceres more interesting than previously tho
 

It's about big enough to be circular. It orbits the sun all by itself. Even has a thin atmosphere (probably). It's a planet, I tell you.

I wonder how much of an atmosphere it could hold if we were to introduce one. What if we were to spin it up to get Earth-like gravity? Would that help, or would we have to dome the entire planet to prevent the atmosphere from escaping? It being only a few hundred Ks across, could we put the entire world into a some kind of giant "buckybubble" instead? Engineering on larger scales- ie thousand-kilometre space elevators- are (apparently) feasible with fullerenes. Bubbling Ceres ought to be relatively easy.


youu'd have to genetically engineer ocean-dwelling bacteria or something that produced blue, rasberry flavour goop...

Mmm... genetically-engineered goop-flavoured blue space-slushie...

Re: OT: Ceres more interesting than previously tho
 

Except pluto is 14 times bigger, and it's status as a planet is often debated. With several objects larger than this outside plutos orbit not getting planetary status, it's unlikely that Ceres will get it. The only thing it has going for it is it is on the same orbital plane.

Re: OT: Ceres more interesting than previously tho
 

Well, 'spinning' to generate artificial gravity works because a mass is reacting against centripetal accelleration... so if you hollowed out the inside, this would work. But then, using gravity to hold in atmosphere becomes a moot point, doesn't it? http://forum.shrapnelgames.com/images/smilies/laugh.gif

Re: OT: Ceres more interesting than previously tho
 

Oh yeah, that does make sense.

It fits in with the bubble idea though. I hereby present:
Crazy-assed "it would never work" scifi mega-engineering project #16b: Dogscoff's Orbital Mega-Aquarium.

1- Move Ceres into a nice, warm orbit. Earth orbit would be nice and convenient, as long as you don't cause any nasty tides back home or anything.

2- While Ceres is in transit, tunnel underneath the ice and start mining the rest of Ceres' material. Store this material in orbit for use in step three.

3- Build a huge, transparent, coin-shaped 'bubble' that completely encompasses Ceres. Dimensions are up to you, I have no idea what you'd need. Your bubble can't be spherical, because you're not going to have any gravity at the poles. The coin must be orbitting in such as way that neither the 'heads' nor 'tails' faces are ever exposed to direct sunlight. Build your docking points and airlocks on the 'heads' and 'tails' faces. If you know how deep your ocean is going to be, you'll know how far from the rim to put these. Meanwhile, the sun is melting Ceres' ice into a vast ocean.

4- Spin the whole affair up to a speed where centripetal force exceeds gravity. Your axis is through the centres of the heads and tails faces. All the water will fly off the surface of Ceres and stick to the curved inside edge of your coin, creating a doughnut-shaped ocean. If you were swimming in this ocean, you'd notice that sunlight is coming up from underneath you and the surface of (what's left of) Ceres itself is hanging ominously above your head.

5- Pull a few appropriate chunks of rocks off of what is left of Ceres, blast them into tiny bits (so they dissolve quicker) and then dump them in the water. This will give you salt water (there's nothing wrong with a freshwater ocean, mind you) but more importantly it will also release some of the water's oxygen to give you something to breathe. I think. You will probably have to tinker with the atmosphere quite a bit to get it breathable.

6- That's it. What you've got is effectively a miniature, enclosed Banksian Orbital, although the way it spins and collects sunlight isn't quite the same. Build yourself a few boats, introduce some plankton and fish and stuff and you're away. If you wanted, and if there's actually anything left of it, you could probably put some upside-down buildings up on the lump of Ceres still hovering in the sky above you. (you fly up and dock on the bottom of the the penthouse, then take the lift up to the ground floor http://forum.shrapnelgames.com/image...s/confused.gif). Alternatively, just remove what remains of it completely, bit by bit, using the material to build luxury liners, surfboards and spaceships. This will make your coin seem lighter and airier, much more Feng-shui than a huge, ugly, scarred and pitted rock o' Doom hovering perpetually in the sky.

Problems:

A- Step one- moving something as big as Ceres from one orbit to another is probably not quite as easy as I make it sound. However I believe it is theoretically feasible, given access to insane quantities of energy and decent spaceflight technology.

B- Step two isn't actually too hard. We might even have the tech to do this now, if someone else could help with the tricky bits (ie steps one, three and four)

C- Step three could be a problem. Materials strong enough for this (and transparent to boot) might not even be possible, let alone obtainable in such massive quantites. Remember your bubble has to support the weight of an entire ocean, it must be rustproof, and be able to withstand the kind of abuse that space throws at it on a regular basis. (radiation, impacts etc)

D- Step four is kind of tricky too by our current standards, but if you can manage steps one and three, this one really is a doddle. In theory, the minimum necessary rotation speed to shed all the water ought to be slightly lower than the speed that would tear Ceres into little pieces, smash your bubble into atoms and give the Earth a pretty planetary ring.

Assuming you've carried out steps one to six successfully, you'll still have some problems.

E- Light. How deep would the ocean be? Too deep to allow any sunlight up to the surface? If this was the case, you could always let some water out until you reach the desired depth. However, you'll always have the problem of keeing the ocean floor clean: As crap builds up down there, it blocks light.

F- Radiation. A certain depth of water would be required to filter out unwanted solar radiation. (That's why you don't want the coin's "heads" or "tails" faces exposed to direct sunlight). This is fine and dandy, but it doens't stop cosmic radiation coming through the heads and tails faces. Maybe these faces could be made opaque. Also, while solar radiation will keep your aquarium's "glass" clear of light-blocking algae, deep-diving creatures (whales, for instance) introduced into the ocean might well get sunburned- not to mention confused- by the sunlight below them. Microwaved Mutant Humpback blubber, anyone?

G- Gravity. I don't know how fast you'd have to spin up your coin to get comfortable gravity, but it's likely to cause some interesting tidal and wind effects.

H- Weather. So the ocean is getting warmed from the bottom up, which ought to create some wierd tidal effects. Also, any water vapour released is going to go... where? Would it all drift inwards and collect in the coin's centre of gravity, freeze and sit there indefinitely, or would it condense and rain back down before it got that far? It all depends of the temperature distributions inside the coin, I guess.

I- Day and night. Is it "day" when the sun is closest to you (ie under your feet) or when it's overhead, with a thousand odd miles of atmosphere, possibly the shrivelled remains of Ceres and a more distant layer of ocean between you and it? How much light would there be on the surface anyway? I think a perpetual (but delightfully sparkly, especially if you introduce some of those luminescent algae) dusky half-light is most likely. You're probably rotating far too fast for any clearly defined day/ night cycle to be comfortable anyway, so maybe this is for the best.

My brain hurts now.

Re: OT: Ceres more interesting than previously tho
 

Step 3 and 4 can be simplified by just reducing the spin.

All you really need is enough spin to keep the water from splashing the remnant of ceres, and with a very slow spin rate you minimize the forces on the outside.

Also, you don't need to spin ceres itself.
Try placing solar sails and/or solar powered ion drives around the outside of the coin for nearly free spin-up thrust.
Use a pump to push water up from ceres to near the edge of the coin, so it catches and starts spinning. The angular momentum will be taken from the coin, but the sails and drives will spin it up again over time.

As you continue to pump, it gets easier and easier to move the water, since the gravity of ceres is decreasing.


If you build just a thin strip of the coin first, you can then winch rocks up from either side of Ceres for use in building more parts of the coin. Cheaper than rockets.
You should also be able to pick out elements to fuel a solar powered ion drive. You'd certainly need a lot of them, but ion drives have great specific impulse, and you have lots of time to work on the project.

Re: OT: Ceres more interesting than previously tho
 

Hell, you mean my crazy-assed idea might even work? Nice one S_J, I'm going to start on it first thing tomorrow. Well, after breakfast, obviously.

Anyone got a stellar manipulation barge I could borrow?

Re: OT: Ceres more interesting than previously tho
 

Oh, and as for the radiation thing... It shouldn't take too much water to block the rads.

What if you just build a double-coin, and fill the space between them with water?

As a bonus, that water barrier will help shield the inside habitat from small asteroid impacts. AND keep the sun-facing surface cool!
You can then let the coin face the sun if you like.

Alternatively, what if you set your coin so that it is not quite edge-on to the sun? Align it so the shadow of the sun-ward dirt bottom does not fall on the far edge of the coin.

At "noon" you'd see the sun just to the left of the skyring.
At midnight, you'd get a few rays glancing up from below only if you are on the far right side of the ring.

Re: OT: Ceres more interesting than previously tho
 

What if you design a material to only let the visible light spectrum, and lower through?

Re: OT: Ceres more interesting than previously tho
 

Beware the mutant fish of DOOM!

I'd use some of that material to build some floating islands.

Re: OT: Ceres more interesting than previously tho
 

That would be handy- not only for the coin but for spaceships and stuff as well.
I remember a short story involving a ship manufacturer who builds all ships completely transparent, and then the buyer just paints in the bits they want covered. Might have been asimov...

Cool. I know I read somewhere that water is a cool rad blocker.

Well you could, but then you start getting into "why not just build a giant space station" territory.

Well, only until the outside barrier gets busted by the first strike and leaks out all the water, surely..?

This is how Banksian Orbitals work. They either have enough atmosphere to soak up the rads, or (more likely) he left the Minds to take care of it with their omnipotent powers. (S_J, have you read any Banks?)

Re: OT: Ceres more interesting than previously tho
 

Its just a simple double-hull idea.

If the water dosen't vaccuum-freeze fast enough to block the hole, you could always pour goop in to make it self-sealing.

Puncture-sealing fluids are advertised all the time these days, for car tires and radiators and whatnot... Just buy some in bulk from Canadian Tire.

If all else fails, pour jello into the outer hull. You could even make the jello armor piece by piece, so you don't have to build the entire outer hull, just a mold for while the jello sets.

Re: OT: Ceres more interesting than previously tho
 

When you put it like that, it makes a lot of sense.

you didn't answer my question: Have you read any Iain M Banks stuff? If not, I'd like to repay the man who introduced me to Schlockmercenary by recommending anything by Iain M Banks. It's about the only scifi I enjoy more than Schlock. You'd love "Against a Dark Background" (For the Lazy Guns) but I think a better introduction to his work might be "Excession" or "Use of Weapons". If you lived near me I'd lend you a copy, but I think it would be easier for you to just click http://www.amazon.ca/exec/obidos/sea...015029-1860360 and splurge a few dollars. Trust me, you will not regret it.

Of course if you've already read it all, forget I spoke.

Re: OT: Ceres more interesting than previously thought
 

.....Is it me or am I the only one who cannot picture Dogscoff's "coin"? http://forum.shrapnelgames.com/image...s/confused.gif

Re: OT: Ceres more interesting than previously tho
 

Can someone draw a diagram? i too cannot picture it...

Re: OT: Ceres more interesting than previously tho
 

Take a ringworld. Shrink it down so that it surrounds the asteroid Ceres instead of a star.
Now build walls over the flat, open spaces.

What you now have, resembes a giant, hollowed-out coin, with the remains of ceres inside.

Re: OT: Ceres more interesting than previously tho
 

What S_J said is dead right, but here's a diagram anyway because I'd already drawn it.

http://www.dogscoff.co.uk/images/mega-fishbowl.jpg

So, the spin of the coin generates centripetal force, which works much the same as gravity, in this case, sticking the ocean, the atmosphere, the people, fish and everything else to the inside edge of the coin. To blatantly steal an analogy from Iain M Banks' "Consider Phlebas": Imagine that you have a bucket of water with a model boat floating on the surface. Now pick up the bucket by the handle and, holding it at arm's length, start to spin it over your head and back down again. As long as you keep spinning it really fast, the water will never fall out of the bucket, and the boat will not sink, even when the bucket is upside down.

Note that the orbit I've drawn in there could be around Earth or around the sun or even around the moon. Doesn't matter, as long as the sunlight only ever comes in through the bottom of the ocean as shown in the picture. This is because the ocean is what filters out all the harmful radiation.

Note also that my diagram does not show the two circular walls that turn the "wedding ring" I've drawn into a "coin". (If you can't get your head around that, think about what you'd need to add to a wedding ring to turn it into a hollow "coin" shape.) These are the two faces I've been referring to as "heads" and "tails", and they are not transparent. They have two main functions:
1- They keep the atmosphere in.
2- The keep harmful cosmic radiation out. Cosmic radiation comes from all directions, not just from the direction of the sun, so the ocean won't block all of it (unless you are in a submarine.)
Your airlocks and space-ship docking would be on the haids and tails faces.

The dimensions of the coin are beyond my mathematical ken, but you're probably looking at a minimum diameter of about a thousand Ks, and a maximum defined purely by the strength of the materials you are building from. Width-wise, it depends largely on the size of Ceres after you've strip-mined and melted it. Probably in the 200-500Ks range.

You might find that you can have a breathable atmosphere sticking to the ocean in much the same way that the ocean sticks to the coin, but that the centre of the coin, around Ceres, is vacuum (or something close to it.)

Oh, and you don't actually need Ceres in the middle there, by the way. You could take it out if you wanted.

Finally, imagine yourself on Narf's boat. Think about where the sunlight is coming from, and how your surroundings would look. Assuming the coin spins once every 24 hours, where will the light be coming from in 12 hours' time?

Re: OT: Ceres more interesting than previously tho
 

From over your head?

Re: OT: Ceres more interesting than previously tho
 

I believe spinning up the astroid would do more harm than good.

At the very least it would do nothing, and at most, it would cause centripetal force to the point that weakens its integrity.

I happen to believe that the 9 hour spin is natural, since gravity is created by the mass of an object, its speed relative to space-time, and the initial alignment of the first atom. I say this because even for Ceres to exist in the first place, it would have had to "settle" into its natural space-time spin, and such a settlement is the lowest-energy result. It would take more energy for it to spin slower, and more mass for it to spin faster.

The best example of this would be to hop on a merry-go-round and have someone toss you a sandbag and for you to bring it to the center of the merry-go-round. As you do, the increased mass equalizes and you spin around much much faster. This is what would happen if you put a large rocket on Ceres to spin it up. But once you remove the rocket, its like throwing the sandbag off the merry-go-round - the mass decreases, and so does the spin. Eventually, as your body returns to the center of the merry-go-round, equilibrium is reached and all that energy you poured into spinning faster was lost to the sandbag you threw off.

If the rocket was ever turned on, though, assuming you could invent the impossible and ensure that the mass you are using to power the rocket wasn't depleted into space as a result (and thus cancel out the effect of the rocket, in a sense, wasting your time), the stability of the merry-go-round would be called into question, and Ceres would fly apart - the natural concequence of adding energy to any object that is already at equilibrium.

So in short: spinning up Ceres would be a physical impossibility because mass is the key ingredient to the gravitational equation.

The best that could be hoped for is some campaign of accreting astroids into it and so increase its mass, but in a controlled manner so as not to obliterate the mass of Ceres that already is stable.

Hollowing out Ceres would more than likely cause Ceres to spin down much slower, to the point that it might even break up entirely. Spinning it up faster to a 1G centriptal force inside a hollowed out band in the core, would probably tear Ceres apart.

The answer would most likely be to find a way to add more mass to Ceres so that 1G centripital could be attained. But then again, if 1G centripital could be obtained, by that point you have enough mass to hold a decent atmosphere and live on the surface.

Except the surface gravity of such a mass would be enough to probably crush you several times over.

Re: OT: Ceres more interesting than previously tho
 

Oh and the coin idea would be great, if it weren't such an engineering challenge to create a transparent material strong enough to hold back an ocean of water from flinging into space. http://forum.shrapnelgames.com/images/smilies/happy.gif

And I don't know if such a boat would float like earth ships, because unlike earth, the deeper in the coin ocean you go, the stronger the centripetal force. I wonder if such a force would practically suck ships down.

Imagine the fish in such an ocean... stuck to the bottom because it takes effort to "climb" up. Swimmers would sink faster than they can float... and boats would have their fishing lines be the straw the breaks the camel's back and starts a chain reation that sucks the whole ship down to the bottom with increasing velocity. Not to mention the force of such a slam on the transparent plating holding in the water.

Sounds like fun!

Re: OT: Ceres more interesting than previously tho
 

Give the size, the gravity change (or force acting like gravity) would not be that sudden. also the water would not need to be that deep, there should only be a few percent difference from the surface to the floor. Even if there was a large change, remember that the water is pulled down just as hard as anything in it. The force that keeps us floating (or swimming)is the pressure of the water below is larger than that above. This would still apply, and a more sudden change in force would magnify this, making it harder to get to the outside wall.

Re: OT: Ceres more interesting than previously tho
 

I would think that it works in theory. But practically, it'd be quite the challenge.

I think it would far easier to build self-replicating robots which would automatically plant rockets on nearby asteroids and slowly drive them towards Ceres for a concerted accretion.

Re: OT: Ceres more interesting than previously tho
 

I think we could just wait till we have artificial gravity.

Re: OT: Ceres more interesting than previously tho
 

If an object's average density is less than water, then it will float in water under one gravity, two, or fifty. However, boat and submarine hulls would be under increased pressure under higher G.

Re: OT: Ceres more interesting than previously tho
 

...Did I miss some basic physics here? Last time I checked, heavier things need more energy to move, and more energy makes things go faster.

Re: OT: Ceres more interesting than previously tho
 

Mass and energy convert between one or the other. The thing with gravity is, you need mass not energy.

Since I believe the spin of a body in space is naturally dependent on mass, by adding mass the spin would increase. By adding energy (which cancels out mass) spin would decrease.

Re: OT: Ceres more interesting than previously tho
 

Heck no.
E = MC^2, remember? Increasing energy -> increasing mass (by a very small amount since c^2 is huge)

The angular momentum of a body depends on its shape, mass and spin rate.
If you make the object smaller it spins faster since the angular momentum must be conserved.
If you add mass without changing the angular momentum, the body will be spinning slower because there is only so much momentum to go around.

The spin of an asteroid is essentially random as the tiny rocks whang it from random directions at random speeds. However there is an upper limit to how fast they could be spinning, since they are generally not solid bodies.
If they spin too fast then rocks on the surface will be swung off by the centrifugal force, and the asteroid breaks up.

Re: OT: Ceres more interesting than previously tho
 

That's my point. To generage 1G of centripetal, the astroid would fly apart, or be so big that you wouldn't need to hollow out the core.

E=MC^2 does not take into account gravitational physics. Einstien couldn't figure out exactly how it played into it.

It is my belief that mass contributes to the natural spin of a body in space-time, up to a certain equilibrium point.

Even though you are correct that initially adding mass to Ceres would cause it to slow down, equilibrium would be reached over time and it would naturally speed up by gravitational physics up to a certain point of equilibrium.

Adding too much mass would obviously cause Ceres to spin down too quickly and the weakened gravity well would essentially force Ceres apart.

What I'm essentially saying is that the faster mass moves, the greater the gravity effect - up to a certain point of course where centripetal force starts to overcome object's structural integrity. This is all due to the increase in mass as energy is converted to mass to move something faster.

By forcing Ceres to spin faster, that balance is offset, and eventually cetripetal force will fly it apart. Mathematically, for purposes of this coin idea, I can guestimate that the centripetal force of a spinning body can never be greater than its optimal gravitational force (and structural integrity).

In short, by the time you could spin Ceres to 1G centripetal force, its would fly apart as 1G of centripetal force would be greater than the escape velocity of the surface which is dependent on the equilibrium of 0.03Gs (guessing its 0.03Gs) generated by Ceres.

That 0.03G is what is holding Ceres together. Force Ceres to spin at a 1G centripetal rate, and you can imagine the concequence.

Re: OT: Ceres more interesting than previously tho
 

What the heck are you talking about? Where did 1G come in?

And WTF is "natural spin"? There is absolutely no preferred spin direction around here in the universe.

Adding too much mass would obviously cause Ceres to spin down too quickly and the weakened gravity well would essentially force Ceres apart.
No way.
More mass -> more gravity.
Slower spin -> less centrifugal force.
Which means objects on the surface feel even more force downwards.
The rate of mass change is completely irrelevant.

This is grade nine or lower physics here.
Please, look up ANGULAR MOMENTUM.

Re: OT: Ceres more interesting than previously tho
 

My info on "natural spin" comes from Dr. Ning Li formerly of the University of Alabama.

I had meant to say that "adding too much mass too quickly would obviously cause Ceres to spin down and the weakened gravity well would essentially allow Ceres to spin itself apart".

This was also with the assumption that rockets were being added to the surface, with enough mass to spin Ceres. That mass would cause Ceres to slow down its spin, destabilizing its gravity well, and the rockets would attempt to spin Ceres in that destabilized condition.

Re: OT: Ceres more interesting than previously tho
 

Reducing spin DOES NOT decrease the gravity by any measureable amount.
The rate at which you add mass means absolutely nothing.

The spin-rockets would have to be landed on the surface carefully, which means matching the spin rate of the surface so as not to plow into the asteroid and leave a crater full of expensive shrapnel. Installing the rockets would not change the spin rate of Ceres, and would increase its mass and angular momentum by an unnoticable fraction.

---

Unfortunately, searching for '"Ning Li" site:ua.edu' turns up zero items.
Ning and Li appear separately, though, as different people.

And if you open it to non - University of Alabama sites relating to spin and gravity, you get a buttload of crackpots, alien/UFO sites and such.

I'm sorry, but Newton's laws are the way it is, to great precision on the scales we are talking about.

Again, this is simple grade 9 physics.
Learn the basics, please.

Re: OT: Ceres more interesting than previously tho
 

Rig up a solar powered superconducting coil, let energy collect, and generate gravity!

Re: OT: Ceres more interesting than previously tho
 

I'm not sure that's the case. What's holding it together is not gravity. Gravity brings the material together in the first place and maybe later compresses it into denser material, but once it's all in place it's the atomic bonds between the atoms making up the rock that keep it from expanding to fill the vacuum around it. Otherwise, small rocks floating alone in space with negligible gravity would spontaneously vapourise the moment they got a sniff of a gravity well, and we know that don't happen.

Here's an experiment you can try at home: Take a big lump of rock. Drill a hole into it and then firmly screw or cement a hook into the hole. Use the hook to suspend the rock from above. Does the rock split in two, with the bottom half shearing away and crashing to the floor because of the 1G force pulling it downwards? Your hook might well pop out, depending on the weight of the rock and your metho of fastening, or the chain or crane might break, but the rock will be just fine.

Anyway, we established some time ago that we don't actually need to alter Ceres' spin at all, just its orbit. It's the coin surrounding Ceres that needs to spin.

And yes, you are right about the amazing properties required of the materials required to build this thing. I stated in an earlier post that such a material might be beyond credibility. However I have a feeling that it might work for smaller coins- perhaps only significantly smaller than Ceres, i don't know (Hell, you could you could use glass and steel up to a kilometre or ten, I reckon)- but I know for a fact that vast, Banksian structures would require bucketloads of unobtainium.

All that said, read up on carbon fullerenes. They have the potential to be insanely strong, and (I believe) transparent too.

Re: OT: Ceres habitat
 

Spin "Gravity" and the gravity from mass are two very very different things. The maximum spin "gravity" you can generate depends mostly on the strength of the steel, Plexiglass, or clear aluminum you use. It also depends some on the radius of your wheel and how much it weights (mass), but only this because it takes a stronger rope to swing a 2 ton bucket around than a 2 kg bucket. The spin would also need to be in the plane of the orbit if you wanted to keep the light coming in through the floor.

There are issues with the conservation of rotational momentum if you want to add more mass to the ring or shift stuff around from the center to the edge. I believe these could be easily solved given that we could build it in the first place. Venus Equilateral lives again! (V.Equ. is a book by the way)

(Edit: what I get for starting and then getting pulled off to work on my real job http://forum.shrapnelgames.com/images/smilies/fear.gif )

Re: OT: Ceres more interesting than previously tho
 

All you gotta do is make the coin spin slow enough for your materials http://forum.shrapnelgames.com/images/smilies/wink.gif. Depending on how much water you want to put in it, that might be significantly less than 1g.

However, even a small fraction of 1g should be sufficient to keep your environmental bits sorted properly. Fishing will certainly be interesting when the bass can jump out of the water and land halfway around the world http://forum.shrapnelgames.com/images/smilies/wink.gif

Re: OT: Ceres more interesting than previously thought
 

/me pictures a fish jumping out of the water and continuing straight up intil it hits water again

/me pictures SJ sitting on a boat with a look on his face saying "OK..... WTF?!?"

Re: OT: Ceres more interesting than previously thought
 

I was also thinking: Assuming you take Ceres out of the coin so that you can have sunlight coming from overhead, and assuming that overhead sunlight is sufficient to live by, you could actually have two landmasses: Each one would be a ring around the coin's circumference, with a ring shaped ocean seperating them. At midday you could look stright up and see the far side of the coin as three stripes: Land, sea, land. The sun would be shining down on you through the distant sea. for people on the far side (midnight for them) it would be dark, unless they were on the water where they'd have bright sunlight shining up at them from underneath.

Strolling along the beach at midnight would be spectacular.

Re: OT: Ceres more interesting than previously thought
 

And instead of jet lag, people would get "strolling lag" as you could probably walk faster than the rotation, and could essentially walk into multiple timzones on just one stroll http://forum.shrapnelgames.com/image...ies/tongue.gif

And riding a speed bike in the opposite direction of the spin would be out of the question - as the faster you travel counter to the direction of spin, the more of the centripetal effect you will negate.

Some interesting side effects: When you jump, you won't always land in the same place you started.

And throwing a football would require additional knowledge of flight trajectory in relation to the spin of the coin, and throw it hard enough, then what goes up most certainly won't come back down. http://forum.shrapnelgames.com/images/smilies/happy.gif

Re: OT: Ceres more interesting than previously thought
 

Inigma, I believe you are confusing force with acceleration. Not hard to do in this context. The "force" being refered to in this thread is similar to gravity, which is technicaly an acceleration, m/s^2. Force, as you are refering to, would be like Newtons, which is Kg*m/s^2. If you work the math out with their label on you will find that it makes more sense.

On that note however, if the ring were 1,000Km it would need the outside of the ring spinning at 2213m/s to achieve 9.7947m/s^2, approximately 1g. Also 1Km in from the surface would still have approximately 9.756m/s^2, less than 1/2 percent difference.

Don't ask me how you could get it to stay together at those speeds though.

I've also found out that about 4 inches (9cm) of water will block gamma rays, 3ft (1m) will block about 20% UV.

Re: OT: Ceres more interesting than previously thought
 

Cool! Numbers! Thanks. I wonder how low you could take the (apparent) gravity for people to feel uncomfortable/ suffer ill health effects. I reckon most ppl (particularly the arthritic and the overweight=-) would enjoy bouncing around in .75G. What about half a G? Fine for an afternoon on the bouncy castle, but what about long term?

Smaller ring and/or settle for lower gravity, I guess. Or use better unobtanium.


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Wow, is that it? I thought it would be a lot more than that. I wonder if NASA's Mars design will have the water tanks wrapped around the ship to shield the crew from radiation. Are those the only dangerous rads to worry about out there, or would there be others?

Re: OT: Ceres more interesting than previously thought
 

UV, X-ray, and gamma rays mostly. stray neutrons could be a problem for deep space/interstellar, possibly. Keep in mind I only found one source for those numbers using google. It is possible there are high level gamma rays not blocked by it. I have heard that some could pass right through the earth, so I'm sure it would only block them to a certain point. I believ in the context of the page refered more to background gamma rays. I'm looking into it further

Re: OT: Ceres more interesting than previously tho
 

Heh, just a wild guess, but I suspect that an active worker in a 0.2g environment would be far healthier than the average north american couch potato. http://forum.shrapnelgames.com/images/smilies/wink.gif

Re: OT: Ceres more interesting than previously tho
 

Is there anything less healthy than an average american couch potato?

Re: OT: Ceres more interesting than previously tho
 

Any kind of radiation harmful to humans has to react/be blocked by something on the order of the thickness of the human body, otherwise it would just go right on through without doing anything. Therefore, it should in principle be possible to build radiation shielding for any conceivable kind of harmful radiation without making it more than a few times as thick as a typical human body.

Re: OT: Ceres more interesting than previously tho
 

Neutron radiation seems to be the most penetrating. They can pass through quite a bit, because of their weight. Not the most abundant type of radiation, but one of the more dangerous. When it is absorbed, it typicaly releases gamma radiation, which must then be shielded against. Earths atmosphere absorb most of it, in fact background radiation at ground level is primarily from the Earth itself. The human body itself does not always stop it, so if you shield stoped the same ammount some would still get through, which could then be absorbed by a human on the other side. Although it does seem water is good at absorbing it. Light atoms absorb more of it, hydrogen is very light, and makes up 2/3 of a water molecule (by number, 11.19% by mass).

Still can't find any good sites on the subject though.

Re: OT: Ceres more interesting than previously tho
 

Just use depleted uranium. Volia, cheap radiation shielding!

Re: OT: Ceres more interesting than previously tho
 

Hmm not sure about the cheap part, especial given the quantitiie invovled.

Someone mentiond story referrencing tranparent shup hulls, the only one i can think of was "ringworld Engineers" by Larry Niven. and the race that built/sold them physically resembled the cue cappa.

As for meterrilas strong enought oto build such a structure. well as someone suggested reguarding Buckyballs i just read a recent article Regaring Carbon nanotubes. They have in th lab at least, created nanotube sheets at rates up 7 Meters per minute. Carbon nanotube cables would have the strength necessary to build a space elevator.
which there has been a revived intrest in, theres now a robotics contest for build a climber.

Re: OT: Ceres more interesting than previously tho
 

I thought depleted uranium emits its own radiation, doesn't it? So although it may stop outside radiation, it probably won't be very healthy to live inside walls made of the material. Also, I don't understand why radiation that passes through the human body won't do any damage. Wouldn't it still do damage as it passes through, just like a bullet that passes through the body?